Vibrato producing means for musical instruments



Dec. 10, 1946. E. F. GERLAT 2,412,212

VIBRATO PRODUCING MEANS FOR MUSICAL INSTRUMENTS Filed Sept. 22, 1944 2 Sheets-Sheet l Patented Dec. 10, 1946 UNl'I'ED STATES PATENT OFFICE VIBRATO PRODUCING MEANS FOR MUSICAL INSTRUMENTS 1 Claim.

This invention relates to musical instruments and has as .its general object the provision of means ior imparting a vibrato quality to the tone of a musical instrument such as a piano.

Another object of this invention is to provide a device capable of imparting a vibrato quality to musical instruments, which is especially applicable to vertical pianos and when applied greatly improves the appearance of the instrument.

Another object of this invention is to provide a device of the character described which may be constructed in various sizes for application to instruments other than pianos and also to loud speakers, particularly of the type employed in connection with electric guitars and similar musical instruments.

A further object of this invention is to provide a device of the character described which is simple and readily applied to a piano or other instrument with which it is to be used.

With the above and other objects in view, which will appear as the description proceeds, this invention resides in the novel construction and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claim, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claim.

The accompanying drawings illustrate several compiete examples of the physical embodiment of the invention constructed in accordance with the best modes so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a perspective view illustrating the manner of applying the device of this invention. to a vertical piano;

Figure 2 is a cross-sectional View taken through Figure 1 on the plane of the line 22;

Figure 3 is a top plan view of the vibrato pro-- ducing device per se;

Figure 4 is a view illustrating the application of this invention to a horizontally strung piano;

Figure 5 is a bottom view of the installation shown in Figure 4;

Figure 6 is a side view with a part broken away and in section illustrating the application of this invention to a loud speaker; and

Figure 7 is a front view of the device shown in Figure 6.

Referring now particularly to the accompanying drawings, in which like numerals indicate like parts, the numeral 5 designates a vertical piano of any conventional type, which, as is customary, is equipped with a sounding board 5 at the back thereof.

The device of this invention, indicated generally by the numeral 1, is applied to the back of the piano and when in position preferably covers the entire back thereof. Essentially the device l consists of an open faced chamber formed by a curved upright wall 8, end walls 9, and a top wall [0. The top wall It has a plurality of ports H, which, together, comprise an outlet.

When in position overlying the back of the piano, where it is held in any suitable manner, as by hooks I2 on the piano and brackets l3 on the side wall 9, the sounding board or back of the piano in general cooperates with the walls of the chamber to define an air column, the outlet or space through which the sound waves move to issue from ports H.

The chamber should fit tightly against the back of the piano and preferably, though not necessarily, a felt packing strip or the like is provided along the vertical and bottom edges of the chamber to seal the juncture between the back of the piano and the edges of the open face of the chamber.

In the upper portion of the chamber is a rotatable butterfly valve I4. This valve extends from end to end of the chamber and is of a size to substantially wholly close the air passage when in a transverse position thus blocking the air column. Consequently, by rotation of the valve M the air column is intermittently interrupted to impart a vibrato quality to the tone of the piano.

Rotation is preferably imparted to the butterfly valve by a small electric motor l5 mounted within the chamber and drivingly connected thereto by a silent belt drive IS. The motor I5 is adapted to be controlled by the operator or player by means of a switch and control cord not shown.

Where the device of this invention is to be applied to a horizontally strung or so-called grand piano, it is mounted under the sounding board, as shown in Figure 4, with the outlet ports ll facing the side of the piano. Obviously, of course, the shape of the chamber must be somewhat altered to have it fit the underside of such a horizontally strung piano, but in its essential characteristics the device is identical with that illustrated in Figures 1, 2 and 3.

In the case of a horizontally strung piano, it is preferable, however, to install a barrier of insulation material over the strings as indicated at ll in Figure 4. This insures the major portion of the tone being dispelled downwardly by the sounding board and through the vibrato producing device.

The application of the invention to loud speakers, as shown in Figures 6 and 7, is substantially the same as that employed in conjunction with a vertical piano excepting that the unit is ,of smaller size and made to fit the front of the cabinet or housing 8 in which the speaker is mounted.

'From the foregoing description, taken in connection with the accompanying drawings, it will be readily apparent to those skilled in the art that this invention provides a novel manner of imparting a vibrato quality to a musical instrument such as a piano, which ordinarily does not possess this characteristic, and that the device of this invention is simple, readily applied and when in position on a vertical piano greatly improves the appearance of its back.

What I claim as my invention is:

An attachment for upright pianos to improve the appearance of the back thereof and to impart a vibrato tone to pianos equipped with the attachment, comprising: a shallow box-like housing opening at its front and having a height and width substantially corresponding to the height and width of the piano for which the attachment is intended; means for attaching the housing to the back of the piano with no portion of the attachment projecting over or to the sides of the piano so that the back wall structure of the piano closes the open front of the attachment by contact with the side and top and bottom edges of the housing walls at said open front thereof, whereby the attachment covers and conceals the back of the piano and cooperates therewith to define a substantially upright tonal passage, said housing having an upper transversely extending wall portion thereof provided with a tonal opening acting as an outlet for said tonal passage; a rotatable valve extending transversely across said tonal passage beneath the tonal opening to intermittently block sound waves moving upwardly along the back wall of the housing towards said tonal opening; and means inside the box-like housing for rotating the valve.

ERVING F. GERLAT. 

